C'è qualcosa che manca in un backup iPhone crittografato?

Ho ricevuto risposta dal supporto di Threema. Le chiavi in realtà sono incluse in un backup di crittografia iTunes, ma possono essere ripristinate sullo stesso dispositivo. Ecco perché consigliano un backup separato.

Hello,

Yes, encrypted iOS backups include the iOS keychain and therefore also the Threema private key; however as it is stored with kSecAttrAccessibleWhenUnlockedThisDeviceOnly, it will additionally be encrypted with the device-specific UID key. Therefore, it will only be usable if restored to the same device that the backup was created on.

Best Regards,

Threema Support

Vorrei postare questa domanda al supporto ragazzi di Threema .

Tuttavia, dal mio punto di vista l'unico modo per ottenere la tua chiave privata dall'iPhone è jailbreak del dispositivo .

Detto questo potrebbe esserci un modo per rimuoverlo dal backup.

Da Apple Developer:

The iOS gives an application access to only its own keychain items.

In iOS, an application always has access to its own keychain items and does not have access to any other application’s items. The system generates its own password for the keychain, and stores the key on the device in such a way that it is not accessible to any application. When a user backs up iPhone data, the keychain data is backed up but the secrets in the keychain remain encrypted in the backup. The keychain password is not included in the backup. Therefore, passwords and other secrets stored in the keychain on the iPhone cannot be used by someone who gains access to an iPhone backup. For this reason, it is important to use the keychain on iPhone to store passwords and other data (such as cookies) that can be used to log into secure web sites.

Tuttavia è ancora compito dello sviluppatore dell'applicazione consentire il backup del portachiavi.